The goal of this proposal is to address serious and ongoing challenges related to adherence to public health recommendations known to reduce the risk of SIDS. Adherence has reached a plateau at an unacceptably low level both in the overall US population and especially in Black infants leading to a halt in the decline in infant mortality and a widening in the racial disparity in infant mortality. The current proposal is a collaborative effort that will capitalize on the extensive experience of the investigators in studying barriers to adherence to safe sleep practices to develop two complementary, culturally competent, intervention strategies and to test the effectiveness of each strategy as well as both strategies in combination. Innovative aspects of the Social Media and Risk-reduction Training of Infant Care Practices (SMART) study include its: 1) unique collaboration of leaders in the field; 2) leveraging of the currently operational infant care practices study infrastructure and hospitals 3) use of two complementary interventions with the potential for synergistic impact; 4) use of social marketing strategies; 5) use of mobile technology (mHealth) to deliver messages; and 6) collaboration with community resources and expertise. The SMART study will have four arms in which 16 hospitals are randomly assigned to one of the following study groups: 1) Safe Sleep Nursery Education and Breastfeeding mHealth messaging; 2) Breastfeeding Nursery Education and Safe Sleep mHealth messaging; 3) Safe Sleep Nursery Education and Safe Sleep mHealth messaging; 4) Breastfeeding Nursery Education and Breastfeeding mHealth messaging. A total of 1600 mothers will be recruited (100/hospital), with 400 in each study group. The primary aim is to assess the effectiveness of the interventions aimed at promoting safe sleep practices compared with the breastfeeding control interventions. The secondary aim is to assess potential mediating factors that may explain the intervention effects on infant care practices and that may inform areas for future improved intervention approaches. With the successful completion of the SMART study, effectiveness data will have been provided for two interventions to improve adherence to safe sleep practices that are practical to disseminate nationally in multiple diverse settings.